https://bugs.documentfoundation.org/show_bug.cgi?id=154181
Bug ID: 154181
Summary: UNO array transfer with 500k elements considerably
slower when running on Java 17 when compared to
running on Java 11
Product: LibreOffice
Version: 7.6.0.0 alpha0+ Master
Hardware: All
OS: Linux (All)
Status: UNCONFIRMED
Severity: normal
Priority: medium
Component: sdk
Assignee: [email protected]
Reporter: [email protected]
Description:
When invoking an interface method that transfers 500k integers (sal_Int32) from
a C++ service to a Java client via UNO, we observe considerable performance
degradation after updating our java runtime to Java 17. On a HP Z640
workstation, we see ~33sec vs. ~16sec when passing -XX:+UseBiasedLocking to the
JVM.
This is due to the following JDK task: https://openjdk.org/jeps/374
And commit:
https://github.com/openjdk/jdk15u/commit/398a2b3c37236c0cd1b5258b517adf9edaf0b044
UseBiasedLocking is marked for deprecation and disabled per default (OpenJDK 19
no longer allows setting -XX:+UseBiasedLocking).
The problem for UNO is as follows: Marshal and Unmarshal use a
ByteArrayOutputStreamDataOutputStream resp.
ByteArrayInputStreamDataInputStream.
1) java.io.ByteArrayInputStream.read() is synchronized and its used to read
everything from the bytes of a transferred message, byte-per-byte (or close
enough to make no difference performance-wise). So for each element in the
array, the code is now taking a lock - the JVM no longer optimizes this away.
2) Same applies for java.io.ByteArrayOutputStream.write(int).
We tried the workaround mentioned below, but for the example above it still
results in about 30% performance degradation (average is at around ~22
seconds).
Is there a more permanent solution that doesn't result in performance
degradation? To our knowledge the synchronization is an accidental byproduct of
using byte array output/input streams.
diff --git a/ridljar/com/sun/star/lib/uno/protocols/urp/Marshal.java
b/ridljar/com/sun/star/lib/uno/protocols/urp/Marshal.java
index 106a8736cb31..5d0150f2ae23 100644
--- a/ridljar/com/sun/star/lib/uno/protocols/urp/Marshal.java
+++ b/ridljar/com/sun/star/lib/uno/protocols/urp/Marshal.java
@@ -15,6 +15,8 @@
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ *
+ * Modifications <C2><A9> 2023 Advantest Corporation
*/
package com.sun.star.lib.uno.protocols.urp;
@@ -210,6 +212,11 @@ final class Marshal {
return data;
}
+ public Object getStreamForSynchronization()
+ {
+ return buffer;
+ }
+
private void writeBooleanValue(Boolean value) throws IOException {
output.writeBoolean(value != null && value.booleanValue());
}
diff --git a/ridljar/com/sun/star/lib/uno/protocols/urp/Unmarshal.java
b/ridljar/com/sun/star/lib/uno/protocols/urp/Unmarshal.java
index c16d19291356..301d4228c52e 100644
--- a/ridljar/com/sun/star/lib/uno/protocols/urp/Unmarshal.java
+++ b/ridljar/com/sun/star/lib/uno/protocols/urp/Unmarshal.java
@@ -15,6 +15,8 @@
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ *
+ * Modifications <C2><A9> 2023 Advantest Corporation
*/
package com.sun.star.lib.uno.protocols.urp;
@@ -157,6 +159,11 @@ final class Unmarshal {
}
}
+ public Object getStreamForSynchronization()
+ {
+ return bytesInput;
+ }
+
public Object readValue(TypeDescription type) {
try {
switch (type.getTypeClass().getValue()) {
@@ -231,7 +238,8 @@ final class Unmarshal {
}
public void reset(byte[] data) {
- input = new DataInputStream(new ByteArrayInputStream(data));
+ bytesInput = new ByteArrayInputStream(data);
+ input = new DataInputStream(bytesInput);
}
private Boolean readBooleanValue() throws IOException {
@@ -471,6 +479,7 @@ final class Unmarshal {
private final ThreadId[] threadIdCache;
private final TypeDescription[] typeCache;
private DataInputStream input;
+ private ByteArrayInputStream bytesInput;
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/ridljar/com/sun/star/lib/uno/protocols/urp/urp.java
b/ridljar/com/sun/star/lib/uno/protocols/urp/urp.java
index 76b5006feb3e..2653e40e4cf5 100644
--- a/ridljar/com/sun/star/lib/uno/protocols/urp/urp.java
+++ b/ridljar/com/sun/star/lib/uno/protocols/urp/urp.java
@@ -16,7 +16,7 @@
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
*
- * Modifications <C2><A9> 2019 Advantest Corporation
+ * Modifications <C2><A9> 2023 Advantest Corporation
*
*/
@@ -106,6 +106,8 @@ public final class urp implements IProtocol {
}
}
UrpMessage msg;
+ synchronized(unmarshal.getStreamForSynchronization()) // fix for
CR-160841
+ {
int header = unmarshal.read8Bit();
if ((header & HEADER_LONGHEADER) != 0) {
if ((header & HEADER_REQUEST) != 0) {
@@ -116,6 +118,8 @@ public final class urp implements IProtocol {
} else {
msg = readShortRequest(header);
}
+ }
+
if (msg.isInternal()) {
handleInternalMessage(msg);
} else {
@@ -163,6 +167,8 @@ public final class urp implements IProtocol {
throws IOException
{
synchronized (output) {
+ synchronized(marshal.getStreamForSynchronization())
+ {
if (PRINT_ALL_IPCS) {
System.out.println("java: writeReply " + result);
}
@@ -204,6 +210,7 @@ public final class urp implements IProtocol {
}
writeBlock(true);
}
+ }
}
private void sendRequestChange() throws IOException {
@@ -540,9 +547,12 @@ public final class urp implements IProtocol {
new QueuedRelease(internal, oid, type, desc, tid));
return false;
} else {
+ synchronized(marshal.getStreamForSynchronization())
+ {
writeQueuedReleases();
return writeRequest(
internal, oid, type, desc, tid, arguments, true);
+ }
}
}
}
Steps to Reproduce:
Transfer a Sequence<sal_Int32> from C++ to a Java client. C++ implementation
looks like this:
Sequence< Sequence< sal_Int32 > > JavaTest::getSequenceOfSequenceOfLongs()
{
int size = 10000;
Sequence<Sequence<sal_Int32>> returnValue(size);
for (sal_Int32 i = 0; i < size; i++) {
returnValue[i] = Sequence< sal_Int32 >(i + 1);
for (sal_Int32 j = 0; j < i + 1; j++) {
returnValue[i][j] = j;
}
}
return returnValue;
}
Actual Results:
33s runtime when using java 17
16s runtime when using java 17 -XX:+UseBiasedLocking
Expected Results:
16s runtime even when not specifying -XX:+UseBiasedLocking
Reproducible: Always
User Profile Reset: No
Additional Info:
n/a
--
You are receiving this mail because:
You are the assignee for the bug.
